Organometallic compound and organic light-emitting device including the same

ABSTRACT

An organometallic compound and an organic light-emitting device including the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of Korean PatentApplication No. 10-2018-0146767, filed on Nov. 23, 2018, and KoreanPatent Application No. 10-2019-0123360, filed on Oct. 4, 2019, each ofwhich is hereby incorporated by reference for all purposes as if fullyset forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate to an organometalliccompound and an organic light-emitting device including the same.

Discussion of the Background

Organic light-emitting devices are self-emission devices that producefull-color images, and also have wide viewing angles, high contrastratios, short response times, and excellent characteristics in terms ofbrightness, driving voltage, and response speed, compared to otherdevices in the art.

The organic light-emitting device may include a first electrode disposedon a substrate, and a hole transport region, an emission layer, anelectron transport region, and a second electrode, which aresequentially disposed on the first electrode. Holes provided from thefirst electrode may move toward the emission layer through the holetransport region, and electrons provided from the second electrode maymove toward the emission layer through the electron transport region.Carriers, such as holes and electrons, recombine in the emission layerto produce excitons. These excitons transit from an excited state to aground state, thereby generating light.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

One or more exemplary embodiments of the invention provide a novelorganometallic compound and an organic light-emitting device includingthe same.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

One or more exemplary embodiments of the inventive concepts includes anorganometallic compound represented by Formula 1:

M(L₁)_(n1)(L₂)_(n2)  <Formula 1>

In Formula 1:

M may be selected from platinum (Pt), palladium (Pd), copper (Cu),silver (Ag), gold (Au), rhodium (Rh), iridium (Ir), ruthenium (Ru),osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu),terbium (Tb), and thulium (Tm);

L₁ may be a ligand represented by Formula 2-1 or 2-2, and n1 is 1, 2, or3, wherein, when n1 is 2 or more, two or more L₁(s) may be identical toor different from each other;

L₂ may be a ligand represented by Formula 3, and n2 may be 0, 1, or 2,wherein, when n2 is 2 or more, two or more L₂(s) may be identical to ordifferent from each other;

the sum of n1 and n2 in Formula 1 may be 2 or 3;

L₁(s) in the number of n1 and L₂(s) in the number of n2 in Formula 1 mayoptionally be linked to each other via a single bond, a first linkinggroup, or a substituted or unsubstituted C₅-C₆₀ carbocyclic group, and asubstituted or unsubstituted C₁-C₆₀ heterocyclic is group;

the first linking group may be selected from *″—N(R₄)—*′″, *″—B(R₄)—*′″,*″—P(R₄)—*′″, *″—C(R₄)(R₅)—*′″, *″—Si(R₄)(R₅)—*′″, *″—Ge(R₄)(R₅)—*′″,*″—S—*′″, *″—Se—*′″, *″—O—*′″, *″—C(═O)—*′″, *″—S(═O)—*′″,*″—S(═O)₂—*′″, *″—C(R₄)═*′, *″═C(R₄)—*′″, *″—C(R₄)═C(R₅)—*′″,*″—C(═S)—*′″, and *″—C≡C—*′″;

A₁ in Formula 2-1 may be selected from a C₅-C₆₀ carbocyclic group and aC₁-C₆₀ heterocyclic group;

X₁ and X₂ in Formula 2-1 may each independently be N or C(R₃);

X₁₁ and X₁₂ in Formula 2-2 may each be C(R₁₅), and X₁₃ may be N orC(R₁₅);

T₂₁ in Formula 3 may be selected from *″—N(R₂₄)—*′″, *″—B(R₂₄)—*′″,*″—P(R₂₄)—*′″, *″—C(R₂₄)(R₂₅)—*′″, *″—Si(R₂₄)(R₂₅)—*′″,*″—Ge(R₂₄)(R₂₅)—*′″, *″—S—*, *″—Se—*′″, *″O—*40 ″, *″—C(═O)—*′″,*″—S(═O)—*′″, *″—S(═O)₂—*′″, *″—C(R₂₄)═*′, *″═C(R₂₄)—*′″,*″—C(R₂₄)═C(R₂₅)—*″, *″—C(═S)—*′″, and *″—C≡C—*′″;

R₁ to R₅, R₁₁ to R₁₅, and R₂₁ to R₂₅ in Formulae 2-1, 2-2, and 3 mayeach independently be selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂);

b1 in Formula 2-1 may be an integer from 1 to 6, wherein, when b1 is 2or more, two or more R₁(s) may be identical to or different from eachother;

b21 to b23 in Formula 3 may each independently be an integer from 1 to3, wherein, when b21 is 2 or more, two or more R₂₁(s) may be identicalto or different from each other, when b22 is 2 or more, two or moreR₂₂(s) may be identical to or different from each is other, and when b23is 2 or more, two or more R₂₃(s) may be identical to or different fromeach other;

in Formulae 2-1, 2-2, and 2-3, two neighboring substituents among R₁(s)in the number of b1, R₂, R₃, R₁₁ to R₁₄, R₁₅, R₂₁(s) in the number ofb21, R₂₂(S) in the number of b22, R₂₃(S) in the number of b23, R₂₄, andR₂₅ may optionally be linked to each other to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group;

a21 in Formula 3 may be an integer from 1 to 3, wherein, when a21 is 2or more, two or more T₂₁(s) may be identical to or different from eachother;

* and *′ in Formulae 2-1 and 2-2 each indicate a binding site to M inFormula 1, and *″ and *′″ in Formulae 1 and 3 each indicate a bindingsite to a neighboring atom;

at least one substituent of the substituted C₅-C₃₀ carbocyclic group,the substituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted C₁-C₆₀heteroaryloxy group, the substituted C₁-C₆₀ heteroarylthio group, thesubstituted monovalent non-aromatic condensed polycyclic group, and thesubstituted monovalent non-aromatic condensed heteropolycyclic group maybe selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independentlybe selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group,a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀alkyl group to substituted with at least one selected from deuterium,—F, —Cl, —Br, —I, and a cyano group, a C₆-C₆₀ aryl group substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, and a cyanogroup, a biphenyl group, and a terphenyl group.

One or more exemplary embodiments of the inventive concepts also providean organic light-emitting device including: a first electrode; a secondelectrode facing the first electrode; an organic layer between the firstelectrode and the second electrode and including an emission layer; andat least one organometallic compound represented by Formula 1.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIGS. 1, 2, 3, and 4 are each a schematic view of an organiclight-emitting device according to an embodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various exemplary embodiments maybe practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid unnecessarilyobscuring various exemplary embodiments. Further, various exemplaryembodiments may be different, but do not have to be exclusive. Forexample, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components, layers,films, regions, and/or aspects, etc. (hereinafter individually or iscollectively referred to as “elements”), of the various embodiments maybe otherwise combined, separated, interchanged, and/or rearrangedwithout departing from the inventive concepts.

In the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order when practicable. Also, like reference numerals denotelike elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. For the purposes of thisdisclosure, “at least one of X, Y, and Z” and “at least one selectedfrom the group consisting of X, Y, and Z” may be construed as X only, Yonly, Z only, or any combination of two or more of X, Y, and Z, such as,for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as toillustrated in the drawings. Spatially relative terms are intended toencompass different orientations of an apparatus in use, operation,and/or manufacture in addition to the orientation depicted in thedrawings. For example, if the apparatus in the drawings is turned over,elements described as “below” or “beneath” other elements or featureswould then be oriented “above” the other elements or features. Thus, theexemplary term “below” can encompass both an is orientation of above andbelow. Furthermore, the apparatus may be otherwise oriented (e.g.,rotated 90 degrees or at other orientations), and, as such, thespatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings.

One or more exemplary embodiments of the inventive concepts include anorganometallic compound represented by Formula 1 below:

M(L₁)_(n1)(L₂)_(n2).  <Formula 1>

In Formula 1, M may be selected from platinum (Pt), palladium (Pd),copper (Cu), silver (Ag), gold (Au), rhodium (Rh), iridium (Ir),ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium(Hf), europium (Eu), terbium (Tb), and thulium (Tm).

In one embodiment, M may be selected from Pt, Ir, Pd, Cu, Ag, and Au.

For example, M may be Pt or Ir, but embodiments of the inventiveconcepts are is not limited thereto:

In Formula 1, L₁ may be a ligand represented by Formula 2-1 or 2-2, andn1 may be 1, 2, or 3, wherein, when n1 is 2 or more, two or more L₁(s)may be identical to or different from each other,

in Formula 1, L₂ may be a ligand represented by Formula 3, and n2 may be0, 1, or 2, wherein, when n2 is 2 or more, two or more L₂(s) may beidentical to or different from each other, and

the sum of n1 and n2 in Formula 1 may be 2 or 3.

In one embodiment, in Formula 1, the sum of n1 and n2 may be 2 and M maybe to Pt; or the sum of n1 and n2 may be 3 and M may be Ir.

For example, in Formula 1, n1 may be 1 and n2 may be 1; or n1 may be 3and n2 may be 0, but embodiments of the inventive concepts are notlimited thereto.

The organometallic compound may include a four-coordinate orsix-coordinate ligand and a metal atom (M₁), and an energy level of atriplet metal centered state (³MC state) of is the organometalliccompound (E_(3MC)) may be higher than an energy level of a tripletmetal-to-ligand charge transfer state (³MLCT state) of theorganometallic compound (E_(3MLCT)).

For example, the organometallic compound may satisfy E₃≥5 kcal/mol, andE₃ may be defined by Equation 1:

E ₃ =∥E _(3MLCT) |−|E _(3MC)∥.  <Equation 1>

In one embodiment, the organometallic compound may satisfy E₃≥5kcal/mol. In one or more embodiments, the organometallic compound maysatisfy E₃≥8 kcal/mol, for example E₃≥19 kcal/mol, for example E₃≥30kcal/mol.

For example, the six-coordinate ligand may have a hemicage or fullcagestructure.

In one embodiment, the organometallic compound may satisfy 5kcal/mol≤E₃≤50 kcal/mol, for example, 8 kcal/mol≤E₃≤30 kcal/mol.

When the organometallic compound satisfies the range of E₃, theprobability that the organometallic compound transitions from the ³MCLTstate to the non-emission state, that is, the ³MC state, decreases.Therefore, the stability of the organometallic compound in an excitedstate may be excellent, and the efficiency and lifespan of the organiclight-emitting device including the organometallic compound mayincrease.

In Formula 1, L₁(s) in the number of n1 and L₂(S) in the number of n2may optionally be linked to each other via a single bond, a firstlinking group, a substituted or unsubstituted C₅-C₆₀ carbocyclic group,or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, and

the first linking group may be selected from *″—N(R₄)—*′″, *″—B(R₄)—*′″,*″—P(R₄)—*′″, *″—C(R₄)(R₅)—*′″, *″—Si(R₄)(R₅)—*′″, *″—Ge(R₄)(R₅)—*′″,*″—S—*′″, *″—Se—*′″, *″—O—*′″, *″ C(═O)—*′″, *″—S(═O)—*′″,*″—S(═O)₂—*′″, *″—C(R₄)═*′, *″═C(R₄)—*′″, *″—C(R₄)═C(R₅)—*″,*″—C(═S)—*′″, and *″—C≡C—*′″.

In one embodiment, n1 and n2 may each be 1, and L₁ may be a grouprepresented by Formula 2-1, and

one of R₁(s) in the number of b1 and one of neighboring R₂₃(S) in thenumber of b23 may be linked to each other via a single bond or a firstlinking group.

For example, one of R₁(s) in the number of b1 and one of neighboringR₂₃(S) in the number of b23 may be linked to each other via a firstlinking group, and the first linking group may be *″—O—*′″, butembodiments of the inventive concepts are not limited thereto.

In one or more embodiments, n1 may be 3, and L₁ may be a grouprepresented by Formula 2-2,

X₁₃(s) in three L₁(s) may each be C(R₁₅),

three R₁₄(s) in three L₁(s) may be linked to each other via asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, and

three R₁₅(s) in three L₁(s) may be linked to each other via asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group.

A₁ in Formula 2-1 may be selected from a C₅-C₆₀ carbocyclic group and aC₁-C₆₀ heterocyclic group.

In one embodiment, A₁ in Formula 2-1 may be selected from:

a benzene group, a pyridine group, a pyrimidine group, a pyrazine group,a pyridazine group, a triazine group, a cyclopentane group, acyclopentadiene group, a furan group, a thiophene group, a pyrrolegroup, a silole group, an oxazole group, an isoxazole group, anoxadiazole group, an isozadiazole group, an oxatriazole group, anisoxatriazole group, a thiazole group, an isothiazole group, athiadiazole group, an isothiadiazole group, a thiatriazole group, anisothiatriazole group, a pyrazole group, an imidazole group, a triazolegroup, a 1,2,4-triazole group, a tetrazole group, an azasilole group, adiazasilole group, a triazasilole group, a cyclohexane group, and acyclohexene group;

a benzene group, a pyridine group, a pyrimidine group, a pyrazine group,a is pyridazine group, a triazine group, a cyclopentane group, acyclopentadiene group, a furan group, a thiophene group, a pyrrolegroup, a silole group, an oxazole group, an isoxazole group, anoxadiazole group, an isozadiazole group, an oxatriazole group, anisoxatriazole group, a thiazole group, an isothiazole group, athiadiazole group, an isothiadiazole group, a thiatriazole group, anisothiatriazole group, a pyrazole group, an imidazole group, a triazolegroup, a 1,2,4-triazole group, a tetrazole group, an azasilole group, adiazasilole group, a triazasilole group, a cyclohexane group, and acyclohexene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a biphenyl group, a terphenyl group, a pentalenyl group, anindenyl group, a naphthyl group, an azulenyl group, an indacenyl group,an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a fluoranthenyl group, atriphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenylgroup, a pentacenyl group, a pyrrolyl group, a thiophenyl group, afuranyl group, a silolyl group, an imidazolyl group, a pyrazolyl group,a thiazolyl group, an isothiazolyl group, an oxazolyl group, anisoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an indolyl group, an isoindolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, an isoquinolinyl group, a phthalazinylgroup, a naphthyridinyl group, a quinoxalinyl group, a benzoquinoxalinylgroup, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinylgroup, a phenanthridinyl group, an acridinyl group, a phenanthrolinylgroup, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group,a benzothiophenyl group, a benzosilolyl group, a benzothiazolyl group, abenzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group,a triazolyl group, a tetrazolyl group, a thiadiazolyl group, anoxadiazolyl group, a triazinyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group,a benzocarbazolyl group, a naphthobenzofuranyl group, anaphthobenzothiophenyl group, a naphthobenzosilolyl group, adibenzocarbazolyl group, a dinaphthofuranyl group, a dinaphthothiophenylgroup, a dinaphtho silolyl group, an imidazopyridinyl group, animidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinylgroup, a benzonaphthyridinyl group, an azafluorenyl group, anazaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranylgroup, an azadibenzothiophenyl group, an azadibenzosilolyl group, anindenopyrrolyl group, an indolopyrrolyl group, an indeno carbazolylgroup, an indolocarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)(Q₃₁), —S(═O)₂(Q₃₁), —P(═O)(Q₃₁)(Q₃₂),and —P(═S)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium,a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, aC₁-C₆₀ alkyl group substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, and a cyano group, a C₆-C₆₀ aryl groupsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,and a cyano group, a biphenyl group, and a terphenyl group.

For example, A₁ may be selected from: a benzene group; and a benzenegroup substituted with at least one selected from deuterium, —F, —Cl,—Br, —I, a cyano group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group,but embodiments of the inventive concepts are not limited thereto.

X₁ and X₂ in Formula 2-1 may each independently be N or C(R₃), and X₁₁and X₁₂ in Formula 2-2 may each independently be C(R₁₅), and X₁₃ inFormula 2-2 may be N or C(R₁₅).

In one embodiment, X₁ and X₂ in Formula 2-1 may each independently beC(R₃), and X₁₃ in Formula 2-2 may be C(R₁₅).

T₂₁ in Formula 3 may be selected from *″—N(R₂₄)—*′″, *″—B(R₂₄)—*′″,*″—P(R₂₄)—*′″, *″—C(R₂₄)(R₂₅)—*′″, *″—Si(R₂₄)(R₂₅)—*′″,*″—Ge(R₂₄)(R₂₅)—*′″, *″—S—*′″, *″—Se—*′″, *″—O—*′″, *″—C(═O)—*′″,*″—S(═O)—*′″, *″—S(═O)₂—*′″, *″—C(R₂₄)═*′, *″═C(R₂₄)—*′″,*″—C(R₂₄)═C(R₂₅)—*″, *″—C(═S)—*′″, and *″—C≡C—*″.

In one embodiment, in Formula 3, T₂₁ may be *″—C(R₂₄)(R₂₅)—*′″, and a21may be 1 or 2.

In Formulae 2-1, 2-2, and 3, R₁ to R₅, R₁₁ to R₁₅, and R₂₁ to R₂₅ mayeach independently be selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂).

When b1 in Formula 2-1 is an integer from 1 to 6, and b1 is 2 or more,two or more R₁(s) may be identical to or different from each other.

When b21 to b23 in Formula 3 are each independently an integer from 1 to3, and b21 is or more, two or more R₂₁(S) may be identical to ordifferent from each other, when b22 is 2 or more, two or more R₂₂(S) maybe identical to or different from each other, and when b23 is 2 or more,two or more R₂₃(S) may be identical to or different from each other.

In Formulae 2-1, 2-2, and 2-3, two neighboring substituents among R₁(s)in the number of b1, R₂, R₃, R₁₁ to R₁₄, R₁₅, R₂₁(S) in the number ofb21, R₂₂(S) in the number of b22, R₂₃(S) in the number of b23, R₂₄, andR₂₅ may optionally be linked to each other to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group.

In one embodiment, in Formulae 2-1, 2-2, and 3, R₁ to R₅, R₁₁ to R₁₅,and R₂₁ to R₂₅ may each independently be selected from: hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy to group;

a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthylgroup, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, apyridazinyl group, a pyrrolyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, and atriazinyl group; and

a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthylgroup, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, apyridazinyl group, an indolyl group, an isoindolyl group, an indazolylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a cinnolinyl group, and a triazinyl group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a phenyl group, anaphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinylgroup, a pyridazinyl group, an indolyl group, an isoindolyl group, anindazolyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, and atriazinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂); and

—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and—P(═O)(Q₁)(Q₂), and

Q₁ to Q₃ and Q₃₁ to Q₃₃ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a C₁-C₂₀ alkylgroup, a C₂-C₂₀ alkenyl group, a C₂-C₂₀ alkynyl group, a C₁-C₂₀ alkoxygroup, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, aC₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₂₀aryl group, a C₁-C₂₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, and a monovalent non-aromatic condensedheteropolycyclic group.

For example, R₂ in Formula 2-1 may be selected from: a C₁-C₂₀ alkylgroup, —N(Q₁)(Q₂), and a phenyl group; and a C₁-C₂₀ alkyl group,—N(Q₁)(Q₂), and a phenyl group, each substituted with a C₁-C₂₀ alkylgroup, and

Q₁ and Q₂ may each independently be a C₁-C₂₀ alkyl group, butembodiments of the inventive concepts are not limited thereto.

For example, R₁₁ and R₁₂ in Formula 2-2 may each independently beselected to from hydrogen, —F, —Cl, a cyano group, a C₁-C₂₀ alkyl group,and a phenyl group, but embodiments of the inventive concepts are notlimited thereto.

a21 in Formula 3 may be an integer from 1 to 3, and when a21 is 2 ormore, two or more T₂₁(s) may be identical to or different from eachother.

* and *′ in Formulae 2-1 and 2-2 each indicate a binding site to M inFormula 1m is and *″ and *′″ in Formulae 1 and 3 each indicate a bindingsite to a neighboring atom.

In one embodiment, the organometallic compound represented by Formula 1may be a group represented by one of Formulae 1-1 to 1-5:

In Formulae 1-1 to 1-5,

L₁₁ to L₁₅ may each independently be selected from a single bond,*″—N(R₄)—*′″, *″—B(R₄)—*′″, *″—P(R₄)*′″*, *″—C(R₄)(R₅)—*′″,*″—Si(R₄)(R₅)—*′″, *″—Ge(R₄)(R₅)—*′″, *″—S—*′″, *″—Se—*′″, *″—O—*′″,*″—C(═O)—*′″, *″—S(═O)—*′″, *″—S(═O)₂—*″, *″—C(R₄)═*′, *″═C(R₄)—*′″,*′″—C(R₄)═C(R₅)—*′″, *″—C(═S)—*′″, and *″—C≡C—*′″,

c11 to c15 may each independently be an integer from 1 to 3, wherein,when c11 is 2 or more, two or more L₁₁(s) may be identical to ordifferent from each other, when c12 is 2 or more, two or more L₁₂(s) maybe identical to or different from each other, when c13 is 2 or more, twoor more L₁₃(s) may be identical to or different from each other, whenc14 is 2 or more, two or more L₁₄(s) may be identical to or differentfrom each other, and when c15 is 2 or more, two or more L₁₅(s) may beidentical to or different from each other,

Ar₁ and Ar₂ may each independently be selected from a substituted orunsubstituted trivalent C₅-C₃₀ carbocyclic group, a substituted orunsubstituted trivalent C₁-C₃₀ heterocyclic group, and a grouprepresented by

Y₄ may be N or C(R₄₀), and *″, *′″, and *″″ each indicate a binding siteto a neighboring atom,

c11 and c12 may each independently be an integer from 1 to 3, wherein,when c11 is 2 or more, two or more L₁₁(s) may be identical to ordifferent from each other, and when c12 is 2 or more, two or more L₁₂(s)may be identical to or different from each other, and

R_(1a) to R_(1c), R_(3a) to R_(3b), R_(15a) to R_(15b), R_(21a) toR_(21c), R_(22a) to R_(22c), R_(23a) to R_(23b), R_(24a) to R_(24b),R_(25a) to R_(25b), and R₃₀ may each independently be the same asdefined in connection with R₁, R₃, R₁₅, and R₂₁ to R₂₅, and R₂, R₄, R₅,and R₁₁ to R₁₃ may each independently be the same as defined inconnection with R₂, R₄, R₅, and R₁₁ to R₁₃.

For example, Ar₁ and Ar₂ may each independently be selected from groupsrepresented by Formula 2A or 2B, but embodiments of the inventiveconcepts are not limited thereto:

In Formulae 2A and 2B,

Y₁ to Y₄ may each independently be N or C(R₄₀), and *″, *′″, and *″″each indicate a binding site to a neighboring atom.

In one embodiment, the organometallic compound may be selected fromCompounds 1 to 14, but embodiments of the inventive concepts are notlimited thereto:

Since the organometallic compound represented by Formula 1 essentiallyincludes a hydroxyl group (—OH group) and a nitrogen atom at a specificposition in a ligand represented by Formula 2-2, stable bluephosphorescence may be emitted through acquisition of attractiveinteraction energy caused by a hydrogen bond between the hydroxyl groupand the nitrogen atom of neighboring ligands.

Since the organometallic compound represented by Formula 1 has astructure in which a carbazole moiety and a pyridine moiety areessentially linked to each other via a linker (T₂₁), as in a ligandrepresented by Formula 3, the lifespan and efficiency of the device maybe improved by a mechanism that greatly increases energy necessary forligand rupture in triplet.

When the organometallic compound represented by Formula 1 optionallyincludes three ligands represented by Formula 2-2, the three ligands arelinked to each other via a group (clipping linker) represented byFormula 2A or 2B. Therefore, the organometallic compound to may have asix-coordinate ligand of a three-dimensional hemicage or fullcagestructure, and the stability and durability of the organometalliccompound may be excellent even in an excited state.

Since the clipping linker links carbocyclic groups or heterocyclicgroups included in the ligand, it is possible to prevent the phenomenonin which, when the organometallic is compound is applied to the organiclight-emitting device, the triplet exciton transitions to thenon-emission state, that is, the ³MC state, by ligand rupture.Therefore, the stability of the organometallic compound in the excitedstate may be excellent, and the lifespan and efficiency of the organiclight-emitting device may be excellent.

In one embodiment, the organometallic compound represented by Formula 1may satisfy the range of E₃ described above. At this time, theprobability that the organometallic compound represented by Formula 1transitions from the ³MCLT state to the non-emission state, that is, the³MC state, decreases. Therefore, the stability of the organometalliccompound in the excited state may be excellent, and the efficiency andlifespan of the organic light-emitting device including theorganometallic compound may increase.

The organometallic compound may emit blue light. For example, theorganometallic compound may emit blue light (bottom emission CIE_(x,y)color coordinates X=0.13, Y=0.05 to 0.18) having a maximum emissionwavelength of about 440 nm or more and about 490 nm or less, butembodiments of the inventive concepts are not limited thereto.Therefore, the organometallic compound represented by Formula 1 may beusefully used for manufacturing an organic light-emitting device thatemits blue light.

A synthesis method for the organometallic compound represented byFormula 1 would be apparent to those of ordinary skill in the art byreferring to the following examples.

At least one of the organometallic compound of Formula 1 may be usedbetween a pair of electrodes of an organic light-emitting device. Forexample, the organometallic compound may be included in an emissionlayer. The organometallic compound may act as a dopant in the emissionlayer. In one or more embodiments, the organometallic compound ofFormula 1 may be used as a material for a capping layer located outsidea pair of electrodes of an organic light-emitting device.

One or more exemplary embodiments of the inventive concepts include anorganic light-emitting device including: a first electrode; a secondelectrode facing the first to electrode; an organic layer between thefirst electrode and the second electrode; and at least oneorganometallic compound represented by Formula 1. For example, theorganic layer includes at least one of organometallic compounds.

The expression “(an organic layer) includes at least one oforganometallic compounds” used herein may include a case in which “(anorganic layer) includes identical organometallic compounds representedby Formula 1” and a case in which “(an organic layer) includes two ormore different organometallic compounds represented by Formula 1”.

For example, the organic layer may include, as the organometalliccompound, only Compound 1. In this regard, Compound 1 may exist only inthe emission layer of the organic light-emitting device. In one or moreembodiments, the organic layer may include, as the organometalliccompound, Compound 1 and Compound 2. In this regard, Compound 1 andCompound 2 may exist in an identical layer (for example, Compound 1 andCompound 2 may all exist in an emission layer), or different layers (forexample, Compound 1 may exist in an emission layer and Compound 2 mayexist in an electron transport region).

According to one embodiment,

the first electrode of the organic light-emitting device may be ananode,

the second electrode of the organic light-emitting device may be acathode, and

the organic layer may further include a hole transport region betweenthe first electrode and the emission layer and an electron transportregion between the emission layer and the second electrode,

the hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof, and

the electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or anycombination thereof.

The term “an organic layer” as used herein refers to a single layerand/or a plurality of layers disposed between the first electrode andthe second electrode of an organic light-emitting device. A materialincluded in the “organic layer” is not limited to an organic material.

In one embodiment, the emission layer includes the organometalliccompound represented by Formula 1. In one embodiment, the emission layerincludes the organometallic compound represented by Formula 1.

In one embodiment, the hole transport region includes an electronblocking layer, which includes the organometallic compound.

In one or more embodiments, the hole transport region includes a holeblocking layer, which includes the organometallic compound.

In one embodiment, the hole transport region may include a p-dopanthaving a is lowest unoccupied molecular orbital (LUMO) energy level of−3.5 eV or less.

FIG. 1 is a schematic cross-sectional view of an organic light-emittingdevice 10 according to an embodiment. The organic light-emitting device10 includes a first electrode 110, an organic layer 150, and a secondelectrode 190.

Hereinafter, the structure of the organic light-emitting device 10according to an embodiment and a method of manufacturing the organiclight-emitting device 10 will be described in connection with FIG. 1.

In FIG. 1, a substrate may be additionally disposed under the firstelectrode 110 or above the second electrode 190. The substrate may be aglass substrate or a plastic substrate, each having excellent mechanicalstrength, thermal stability, transparency, surface smoothness, ease ofhandling, and water resistance.

The first electrode 110 may be formed by depositing or sputtering amaterial for forming the first electrode 110 on the substrate. When thefirst electrode 110 is an anode, the material for forming the firstelectrode 110 may be selected from materials with a high work functionto facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-reflectiveelectrode, or a transmissive electrode. When the first electrode 110 isa transmissive electrode, a material for forming a first electrode maybe selected from indium tin oxide (ITO), indium zinc oxide (IZO), tinoxide (SnO₂), zinc oxide (ZnO), and any combinations thereof, butembodiments of the inventive concepts are not limited thereto. In one ormore embodiments, when the first electrode 110 is a semi-transmissiveelectrode or a reflective electrode, a material for forming a firstelectrode may be selected from magnesium (Mg), silver (Ag), aluminum(Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),magnesium-silver (Mg—Ag), and any combinations thereof, but embodimentsof the inventive concepts are not limited thereto.

The first electrode 110 may have a single-layered structure, or amulti-layered structure including two or more layers. For example, thefirst electrode 110 may have a three-layered structure of ITO/Ag/ITO,but the structure of the first electrode 110 is not limited thereto.

The organic layer 150 is disposed on the first electrode 110. Theorganic layer 150 may include an emission layer.

The organic layer 150 may further include a hole transport regionbetween the first electrode 110 and the emission layer and an electrontransport region between the emission layer and the second electrode190.

The hole transport region in organic layer 150 may have i) asingle-layered structure including a single layer including a singlematerial, ii) a single-layered structure including a single layerincluding a plurality of different materials, or iii) a multi-layeredstructure having a plurality of layers including a plurality ofdifferent materials.

The hole transport region may include at least one layer selected from ahole injection layer, a hole transport layer, an emission auxiliarylayer, and an electron blocking layer.

For example, the hole transport region may have a single-layeredstructure including a single layer including a plurality of differentmaterials, or a multi-layered structure having a hole injectionlayer/hole transport layer structure, a hole injection layer/holetransport layer/emission auxiliary layer structure, a hole injectionlayer/emission auxiliary layer structure, a hole transportlayer/emission auxiliary layer structure, or a hole injection layer/holetransport layer/electron blocking layer structure, wherein for eachstructure, constituting layers are sequentially stacked from the firstelectrode 110 in this stated order, but the structure of the holetransport region is not limited thereto.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may optionally be linked toeach other via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be linked toeach other via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group.

In one embodiment, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl is group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1,or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independentlybe selected from a phenyl group, a biphenyl group, a terphenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group,an indenyl group, a naphthyl group, an azulenyl group, a heptalenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl togroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ are the same as described above.

In one or more embodiments, at least one selected from R₂₀₁ to R₂₀₃ inFormula 201 may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a naphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranylgroup, and a dibenzothiophenyl group,

but embodiments of the inventive concepts are not limited thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may belinked to to each other via to each other via a single bond, and/or ii)R₂₀₃ and R₂₀₄ may be linked to each other via a single bond.

In one or more embodiments, at least one selected from R₂₀₁ to R₂₀₄ inFormula 202 may each independently be selected from:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, acarbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the inventive concepts are not limited thereto.

The compound represented by Formula 201 may be represented by Formula201-1 below:

In one embodiment, the compound represented by Formula 201 may berepresented by Formula 201-2 below, but embodiments of the inventiveconcepts are not limited thereto:

In one or more embodiments, the compound represented by Formula 201 maybe represented by Formula 201-2(1) below, but embodiments of theinventive concepts are not limited thereto:

In one or more embodiments, the compound represented by Formula 201 maybe represented by Formula 201A below:

In one or more embodiments, the compound represented by Formula 201 maybe represented by Formula 201A(1) below, but embodiments of theinventive concepts are not limited thereto:

In one or more embodiments, the compound represented by Formula 201 maybe represented by Formula 201A-1 below, but embodiments of the inventiveconcepts are not limited thereto:

In one embodiment, the compound represented by Formula 202 may berepresented by Formula 202-1 below:

In one or more embodiments, the compound represented by Formula 202 maybe represented by Formula 202-1(1) below:

In one or more embodiments, the compound represented by Formula 202 maybe represented by Formula 202A below:

In one or more embodiments, the compound represented by Formula 202 maybe represented by Formula 202A-1 below:

In Formulae 201-1, 201-2, 201-2(1), 201A, 201A(1), 201A-1, 202-1,202-1(1), 202A, and 202A-1,

L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ are the same asdescribed above,

L₂₀₅ may be selected from a phenylene group and a fluorenylene group,

X₂₁₁ may be selected from O, S, and N(R₂₁₁),

X₂₁₂ may be selected from O, S, and N(R₂₁₂),

R₂₁₁ and R₂₁₂ are each the same as defined in connection with R₂₀₃, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group.

The hole transport region may include at least one compound selectedfrom Compounds HT1 to HT48, but embodiments of the inventive conceptsare not limited thereto:

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When thehole transport region includes at least one selected from a holeinjection layer and a hole transport layer, the thickness of the holeinjection layer may be in a range of about 100 Å to about 9,000 Å, andfor example, about 100 Å to about 1,000 Å, and the thickness of the holetransport layer may be in a range of about 50 Å to about 2,000 Å, andfor example, about 100 Å to about 1,500 Å. When the thicknesses of thehole transport region, the hole injection layer, and the hole transportlayer are within these ranges, satisfactory hole transportingcharacteristics may be obtained without a substantial increase indriving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by to an emission layer, and the electronblocking layer may block the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the materials as described above.

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation is material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant.

In one embodiment, the p dopant may have a LUMO energy level of −3.5 eVor less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butembodiments of the inventive concepts are not limited thereto.

In one embodiment, the p-dopant may include at least one selected from:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide or molybdenum oxide;

1,4,5,8,9,12-Hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221 below,

but embodiments of the inventive concepts are not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, wherein at least oneselected from R₂₂₁ to R₂₂₃ may have at least one substituent selectedfrom a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substitutedwith —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

When the organic light-emitting device 10 is a full-color organiclight-emitting device, the emission layer in organic layer 150 may bepatterned into a red emission layer, a green emission layer, or a blueemission layer, according to a sub-pixel. In one or more embodiments,the emission layer may have a stacked structure of two or more layersselected from a red emission layer, a green emission layer, and a blueemission layer, in which the two or more layers contact each other orare separated from each other. In one or more embodiments, the emissionlayer may include two or more materials selected from a redlight-emitting material, a green light-emitting material, and a bluelight-emitting material, in which the two or more materials are mixedwith each other in a single layer to emit white light.

The emission layer may include a host and a dopant. The dopant mayinclude at least one selected from a phosphorescent dopant and afluorescent dopant. The phosphorescent dopant may include theorganometallic compound represented by Formula 1.

In the emission layer, an amount of the dopant may be in a range ofabout 0.01 parts by weight to about 15 parts by weight based on 100parts by weight of the host, but embodiments of the inventive conceptsare not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. When thethickness of the emission layer is within this range, excellentlight-emission characteristics may be obtained without a substantialincrease in driving voltage.

In one or more embodiments, the host in the emission layer may include acompound represented by Formula 301 below:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  <Formula 301>

In Formula 301,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5, and

Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but embodiments of the inventiveconcepts are not limited thereto.

In one embodiment, Ar₃₀₁ in Formula 301 may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group, but embodiments of the inventive conceptsare not limited thereto.

When xb11 in Formula 301 is 2 or more, two or more Ar₃₀₁(s) may belinked to each other via a single bond.

In one or more embodiments, the compound represented by Formula 301 maybe represented by Formula 301-1 or 301-2:

In Formulae 301-1 and 301-2,

ring A₃₀₁ to ring A₃₀₄ may each independently be selected from a benzenering, a naphthalene ring, a phenanthrene ring, a fluoranthene ring, atriphenylene ring, a pyrene ring, a chrysene ring, a pyridine ring, apyrimidine ring, an indene ring, a fluorene ring, a spiro-bifluorenering, a benzofluorene ring, a dibenzofluorene ring, an indole ring, acarbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a furanring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, abenzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring, abenzothiophene ring, a dibenzothiophene ring, a naphthothiophene ring, abenzonaphthothiophene ring, and a dinaphthothiophene ring,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ are each the same as described above,

L₃₀₂ to L₃₀₄ are each independently the same as described in connectionwith L₃₀₁,

xb2 to xb4 each independently the same as described in connection withxb1, and

R₃₀₂ to R₃₀₄ each independently the same as described in connection withR₃₀₁.

For example, in Formulae 301, 301-1, and 301-2, L₃₀₁ to L₃₀₄ may each toindependently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, is a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ are the same as described above.

In one embodiment, in Formulae 301, 301-1, and 301-2, R₃₀₁ to R₃₀₄ mayeach independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ are the same as described above.

In one embodiment, the host may include an alkaline earth-metal complex.For example, the host may be selected from a Be complex (for example,Compound H55), a Mg complex, and a Zn complex.

In one or more embodiments, the host may include at least one selectedfrom 9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55,but embodiments of the inventive concepts are not limited thereto:

In one embodiment, the host may include at least one selected from asilicon-containing compound (for example, BCPDS used in the followingexamples or the like) and a phosphine oxide-containing compound (forexample, POPCPA used in the following examples or the like).

In one embodiment, the host may include only one compound, or two ormore different compounds (for example, a host used in the followingexamples includes BCPDS and POPCPA).

The phosphorescent dopant included in the emission layer in organiclayer 150 to may include an organometallic compound represented byFormula 1:

In addition, the phosphorescent dopant may include an organometalliccomplex represented by Formula 401 below:

M(L₄₀₁)_(xc1)(L₄₀₂)_(xc2)  <Formula 401>

In Formulae 401 and 402,

M may be selected from Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Rh, and Tm,

L₄₀₁ may be selected from ligands represented by Formula 402, and xc1may be 1, 2, or 3, wherein, when xc1 is 2 or more, two or more L₄₀₁(s)may be identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer from 0 to 4,wherein, when xc2 is 2 or more, two or more L₄₀₂(s) may be identical toor different from each other,

X₄₀₁ to X₄₀₄ may each independently be nitrogen or carbon,

X₄₀₁ and X₄₀₃ may be linked to each other via a single bond or a doublebond, and X₄₀₂ and X₄₀₄ may be linked to each other via a single bond ora double bond,

A₄₀₁ and A₄₀₂ may each independently be selected from a C₅-C₆₀carbocyclic group or a C₁-C₆₀ heterocyclic group,

X₄₀₅ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′,*—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)═C(Q₄₁₂)—*′, *—C(Q₄₁₁)═*′, or *═C═*′,wherein Q₄₁₁ and Q₄₁₂ may each independently be hydrogen, deuterium, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenylgroup, a terphenyl group, or a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, asubstituted or unsubstituted C₁-C₂₀ alkyl group, a substituted orunsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃),—N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and—P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁ to Q₄₀₃ may each independently beselected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ arylgroup, and a C₁-C₂₀ heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

In one embodiment, A₄₀₁ and A₄₀₂ in Formula 402 may each independentlybe selected from a benzene group, a naphthalene group, a fluorene group,a spiro-bifluorene group, an indene group, a pyrrole group, a thiophenegroup, a furan group, an imidazole group, a pyrazole group, a thiazolegroup, an isothiazole group, an oxazole group, an isoxazole group, a ispyridine group, a pyrazine group, a pyrimidine group, a pyridazinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a quinoxaline group, a quinazoline group, a carbazole group, abenzimidazole group, a benzofuran group, a benzothiophene group, anisobenzothiophene group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, andX₄₀₂ may be carbon, or ii) X₄₀₁ and X₄₀₂ may be nitrogen at the sametime.

In one or more embodiments, R₄₀₁ and R₄₀₂ in Formula 402 may eachindependently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group,a cyclohexyl group, an adamantanyl group, a norbornanyl group, and anorbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group a phenyl group, a biphenyl group,a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁),—S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), and

Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, and anaphthyl group, but embodiments of the inventive concepts are notlimited thereto.

In one or more embodiments, when xc1 in Formula 401 is 2 or more, twoA₄₀₁(s) in two or more L₄₀₁(s) may optionally be linked to each othervia X₄₀₇, which is a linking group, or two A₄₀₂(s) in two or moreL₄₀₁(s) may optionally be linked to each other via X₄₀₈, which is alinking group (see Compounds PD1 to PD4 and PD7). X₄₀₇ and X₄₀₈ may eachindependently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′,*—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Q₄₁₃)═C(Q₄₁₄)-*′ (wherein Q₄₁₃and Q₄₁₄ may each independently be hydrogen, deuterium, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, or a naphthyl group), but embodiments of the inventiveconcepts are not limited thereto.

L₄₀₂ in Formula 401 may be a monovalent, divalent, or trivalent organicligand. For example, L₄₀₂ may be selected from halogen, diketone (forexample, acetylacetonate), carboxylic acid (for example, picolinate),—C(═O), isonitrile, —CN, and a phosphorus-containing material (forexample, phosphine, or phosphite), but embodiments of the inventiveconcepts are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selectedfrom, for example, Compounds PD1 to PD25, but embodiments of theinventive concepts are not to limited thereto:

The fluorescent dopant in the emission layer may include an arylaminecompound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501below:

In Formula 501,

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xd1 to xd may each independently be an integer from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and

xd4 may be an integer from 1 to 6.

In one embodiment, Ar₅₀₁ in Formula 501 may be selected from:

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup; and

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup, each substituted with at least one is selected from deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In one or more embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may eachindependently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl is group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group.

In one or more embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may eachindependently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodimentsof the inventive concepts are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1to FD22:

In one or more embodiments, the fluorescent dopant may be selected fromthe following compounds, but embodiments of the inventive concepts arenot limited thereto:

The electron transport region in organic layer 150 may have i) asingle-layered structure including a single layer including a singlematerial, ii) a single-layered structure including a single layerincluding a plurality of different materials, or iii) a multi-layeredstructure having a plurality of layers including a plurality ofdifferent materials.

The electron transport region may include at least one layer selectedfrom a buffer layer, a hole blocking layer, an electron control layer,an electron transport layer, and an electron injection layer, butembodiments of the inventive concepts are not limited thereto.

For example, the electron transport region may have an electrontransport to layer/electron injection layer structure, a hole blockinglayer/electron transport layer/electron injection layer structure, anelectron control layer/electron transport layer/electron injection layerstructure, or a buffer layer/electron transport layer/electron injectionlayer structure, wherein for each structure, constituting layers aresequentially stacked from an emission layer. However, embodiments of thestructure of the electron transport region are not limited thereto.

The electron transport region (for example, a buffer layer, a holeblocking layer, an electron control layer, or an electron transportlayer in the electron transport region) may include a metal-freecompound containing at least one π electron-depleted nitrogen-containingring.

The “π electron-depleted nitrogen-containing ring” indicates a C₁-C₆₀heterocyclic group having at least one *—N═*′ moiety as a ring-formingmoiety.

For example, the “π electron-depleted nitrogen-containing ring” may bei) a 5-membered to 7-membered heteromonocyclic group having at least one*—N═*′ moiety, ii) a heteropolycyclic group in which two or more5-membered to 7-membered heteromonocyclic groups each having at leastone *—N═*′ moiety are condensed with each other, or iii) aheteropolycyclic group in which at least one of 5-membered to 7-memberedheteromonocyclic groups, each having at least one *—N═*′ moiety, iscondensed with at least one C₅-C₆₀ carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring include animidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring,an oxazole ring, an isoxazole ring, a pyridine ring, a pyrazine ring, apyrimidine ring, a pyridazine ring, an indazole ring, a purine ring, aquinoline ring, an isoquinoline ring, a benzoquinoline ring, aphthalazine ring, a naphthyridine ring, a quinoxaline ring, aquinazoline ring, a cinnoline ring, a phenanthridine ring, an acridinering, a phenanthroline ring, a phenazine ring, a benzimidazole ring, anisobenzothiazole ring, a benzoxazole ring, an isobenzoxazole ring, atriazole ring, a tetrazole ring, an oxadiazole ring, a triazine ring, athiadiazole ring, an imidazopyridine ring, an imidazopyrimidine ring,and an azacarbazole ring, but are not limited thereto.

For example, the electron transport region may include a compoundrepresented by Formula 601 below:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  <Formula 601>

In Formula 601,

Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group, and

xe21 may be an integer from 1 to 5.

In one embodiment, at least one of Ar₆₀₁(s) in the number of xe11 andR₆₀₁(s) in the number of xe21 may include the it electron-depletednitrogen-containing ring.

In one embodiment, Ar₆₀₁ in Formula 601 may be selected from:

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene is group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

When xe11 in Formula 601 is 2 or more, two or more Ar₆₀₁(s) may belinked to each other via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracenegroup.

In one or more embodiments, a compound represented by Formula 601 may berepresented by Formula 601-1 below:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be the same as described inconnection with L₆₀₁,

xe611 to xe613 may each independently be defined the same as xe1,

R₆₁₁ to R₆₁₃ may each independently be the same as described inconnection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In one embodiment, L₆₀₁ and L₆₁₁ to L₆₁₃ in Formulae 601 and 601-1 mayeach independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, to a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl isgroup, an anthracenyl group, a fluoranthenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a perylenyl group, apentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, an imidazolyl group, a pyrazolyl group, a thiazolyl group, anisothiazolyl group, an oxazolyl group, an isoxazolyl group, athiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinylgroup, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinylgroup, a naphthyridinyl group, a quinoxalinyl group, a quinazolinylgroup, a cinnolinyl group, a phenanthridinyl group, an acridinyl group,a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, animidazopyrimidinyl group, and an azacarbazolyl group,

but embodiments of the inventive concepts are not limited thereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and601-1 may each independently be 0, 1, or 2.

In one or more embodiments, R₆₀₁ and R₆₁₁ to R₁₃ in Formula 601 and601-1 may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl to group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl is group, a pyridazinyl group, atriazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂), and

Q₆₀₁ and Q₆₀₂ are the same as described above.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET36, but embodiments of the inventive conceptsare not limited thereto:

In one embodiment, the electron transport region may include at leastone selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-dphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), and NTAZ:

In one or more embodiments, the electron transport region may include aphosphine oxide-containing compound, but embodiments of the inventiveconcepts are not limited thereto. In one embodiment, the phosphineoxide-containing compound may be used in a hole blocking layer in theelectron transport region, but embodiments of the inventive concepts arenot limited thereto.

Thicknesses of the buffer layer, the hole blocking layer, and theelectron control layer may each be in a range of about 20 Å to about1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses ofthe buffer layer, the hole blocking layer, and the electron control tolayer are within these ranges, the electron blocking layer may haveexcellent electron blocking characteristics or electron controlcharacteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whenthe thickness of the electron transport layer is within the rangedescribed above, the electron transport layer may have is satisfactoryelectron transport characteristics without a substantial increase indriving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include at least one selected fromalkali metal complex and alkaline earth-metal complex. The alkali metalcomplex may include a metal ion selected from a Li ion, a Na ion, a Kion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex mayinclude a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Srion, and a Ba ion. A ligand coordinated with the metal ion of the alkalimetal complex or the alkaline earth-metal complex may be selected from ahydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, ahydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, ahydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, and a cyclopentadiene, but embodiments of the inventiveconcepts are not limited thereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (lithium quinolate,LiQ) or ET-D2:

The electron transport region may include an electron injection layerthat facilitates electron injection from the second electrode 190. Theelectron injection layer may directly contact the second electrode 190.

The electron injection layer may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In oneembodiment, the alkali metal may be Li, Na, or Cs. In one or moreembodiments, the alkali metal may be Li or Cs, but embodiments of theinventive concepts are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and therare earth metal compound may be selected from oxides and halides (forexample, fluorides, chlorides, bromides, or iodides) of the alkalimetal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, suchas Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF,KF, LiI, NaI, CsI, or KI. In one embodiment, the alkali metal compoundmay be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, to and KI, butembodiments of the inventive concepts are not limited thereto.

The alkaline earth-metal compound may be selected from alkalineearth-metal oxides, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), orBa_(x)Ca_(1-x)O (0<x<1). In one embodiment, the alkaline earth-metalcompound may be selected from BaO, SrO, and CaO, but embodiments of theinventive concepts are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, ScO₃,Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In one embodiment, the rare earthmetal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, andTb₃, but embodiments of the inventive concepts are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include an ion of alkali metal, alkalineearth-metal, and rare earth metal as described above, and a ligandcoordinated with a metal ion of the alkali metal complex, the alkalineearth-metal complex, or the rare earth metal complex may be selectedfrom hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline,hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxyphenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole,hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene,but embodiments of the inventive concepts are not limited thereto.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof, as described above. In one or moreembodiments, the electron injection layer may further include an organicmaterial. When the electron injection layer further includes an organicmaterial, an alkali metal, an alkaline earth metal, a rare earth metal,an alkali metal compound, an alkaline earth-metal compound, a rare earthmetal compound, an alkali metal complex, an alkaline earth-metalcomplex, a rare earth metal complex, or any combinations thereof may behomogeneously or non-homogeneously dispersed in a matrix including theorganic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. When thethickness of the electron injection layer is within the range describedabove, the electron injection layer may have satisfactory electroninjection characteristics without a substantial increase in drivingvoltage.

The second electrode 190 may be disposed on the organic layer 150 havingsuch a structure. The second electrode 190 may be a cathode which is anelectron injection electrode, and in this regard, a material for formingthe second electrode 190 may be selected from metal, an alloy, anelectrically conductive compound, and a combination thereof, which havea is relatively low work function.

The second electrode 190 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but embodiments of the inventive concepts are notlimited thereto. The second electrode 190 may be a transmissiveelectrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

FIG. 2 is a schematic view of an organic light-emitting device 20according to an embodiment. The organic light-emitting device 20includes a first capping layer 210, the first electrode 110, the organiclayer 150, and the second electrode 190, which are sequentially stackedin this stated order. FIG. 3 is a schematic view of an organiclight-emitting device 30 according to an embodiment. The organiclight-emitting device 30 includes the first electrode 110, the organiclayer 150, the second electrode 190, and a second capping layer 220,which are sequentially stacked in this stated order. FIG. 4 is aschematic view of an organic light-emitting device 40 according to anembodiment. The organic light-emitting device 40 includes the firstcapping layer 210, the first electrode 110, the organic layer 150, thesecond electrode 190, and the second capping layer 220, which aresequentially stacked in this stated order.

Regarding FIGS. 2, 3, and 4, the first electrode 110, the organic layer150, and the second electrode 190 may be understood by referring to thedescription presented in connection with FIG. 1.

In the organic layer 150 of each of the organic light-emitting devices20 and 40, light generated in an emission layer may pass through thefirst electrode 110 and the first capping layer 210 toward the outside,wherein the first electrode 110 may be a semi-transmissive electrode ora transmissive electrode. In the organic layer 150 of each of theorganic light-emitting devices 30 and 40, light generated in an emissionlayer may pass through the second to electrode 190 and the secondcapping layer 220 toward the outside, wherein the second electrode 190may be a semi-transmissive electrode or a transmissive electrode.

The first capping layer 210 and the second capping layer 220 mayincrease external luminescence efficiency according to the principle ofconstructive interference.

The first capping layer 210 and the second capping layer 220 may each isindependently be an organic capping layer including an organic material,an inorganic capping layer including an inorganic material, or acomposite capping layer including an organic material and an inorganicmaterial.

At least one selected from the first capping layer 210 and the secondcapping layer 220 may each independently include at least one materialselected from carbocyclic compounds, heterocyclic compounds, amine-basedcompounds, porphyrine derivatives, phthalocyanine derivatives, anaphthalocyanine derivatives, alkali metal complexes, and alkalineearth-based complexes. The carbocyclic compound, the heterocycliccompound, and the amine-based compound may be optionally substitutedwith a substituent containing at least one element selected from O, N,S, Se, Si, F, Cl, Br, and I. In one embodiment, at least one selectedfrom the first capping layer 210 and the second capping layer 220 mayeach independently include an amine-based compound.

In one embodiment, at least one selected from the first capping layer210 and the second capping layer 220 may each independently include thecompound represented by Formula 201 or the compound represented byFormula 202.

In one or more embodiments, at least one selected from the first cappinglayer 210 and the second capping layer 220 may each independentlyinclude a compound selected from Compounds HT28 to HT33 and CompoundsCP1 to CP5, but embodiments of the inventive concepts are not limitedthereto:

Hereinbefore, the organic light-emitting device according to anembodiment has been described in connection with FIGS. 1 to 4, butembodiments of the inventive concepts are not limited thereto.

Layers constituting the hole transport region, an emission layer, andlayers constituting the electron transport region may be formed in acertain region by using one or more suitable methods selected fromvacuum deposition, spin coating, casting, Langmuir-Blodgett to (LB)deposition, ink-jet printing, laser-printing, and laser-induced thermalimaging.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec is by taking into account a material to be includedin a layer to be formed, and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed by spincoating, the spin coating may be performed at a coating speed of about2,000 rpm to about 5,000 rpm and at a heat treatment temperature ofabout 80° C. to 200° C. by taking into account a material to be includedin a layer to be formed, and the structure of a layer to be formed.

General Definition of Substituents:

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic saturated hydrocarbon monovalent group having 1 to 60carbon atoms, and examples thereof include a methyl group, an ethylgroup, a propyl group, an isobutyl group, a sec-butyl group, atert-butyl group, a pentyl group, an isoamyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon double bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkenylene group” as used herein refers to a divalent group having theis same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon triple bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group”as used herein refers to a divalent group having the same structure asthe C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andexamples thereof include a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term“C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent grouphaving the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent monocyclic group having at least one heteroatom selected fromN, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, andexamples thereof include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term C₃-C₁₀ cycloalkenyl group used herein refers to a monovalentmonocyclic group that has 3 to 10 carbon atoms and at least onecarbon-carbon double bond in the ring thereof and no aromaticity, andexamples thereof include a cyclopentenyl group, a cyclohexenyl group,and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” asused herein refers to a divalent group having the same structure as theC₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one carbon-carbon double bond in its ring. Non-limitingexamples of the C₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, and aC₆-C₆₀ arylene group used herein refers to a divalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms. Non-limitingexamples of the C₆-C₆₀ aryl group include a phenyl group, a naphthylgroup, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, anda chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylenegroup each include two or more rings, the rings may be fused to eachother.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a carbocyclic aromatic system that has at least oneheteroatom selected from N, O, Si, P, and S as a ring-forming atom, inaddition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group”as used herein refers to a divalent group having a carbocyclic aromaticsystem that has at least one heteroatom selected from N, O, Si, P, and Sas a ring-forming atom, in addition to 1 to 60 carbon atoms.Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinylgroup, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, and an isoquinolinyl group. Whenthe C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group eachinclude two or more rings, the rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group used hereinindicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed with each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. A detailed example of the monovalent non-aromatic condensedpolycyclic group is a fluorenyl group. The term “divalent non-aromaticcondensed polycyclic group” as used herein refers to a divalent grouphaving the same structure as the monovalent non-aromatic condensedpolycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 1 to 60carbon atoms) having two or is more rings condensed to each other, atleast one heteroatom selected from N, O, Si, P, and S, other than carbonatoms, as a ring-forming atom, and no aromaticity in its entiremolecular structure. An example of the monovalent non-aromatic condensedheteropolycyclic group is a carbazolyl group. The term “divalentnon-aromatic condensed heteropolycyclic group” as used herein refers toa divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₄-C₆₀ carbocyclic group” as used herein refers to amonocyclic or polycyclic group having 4 to 60 carbon atoms in which aring-forming atom is a carbon atom only. The term “C₄-C₆₀ carbocyclicgroup” as used herein refers to an aromatic carbocyclic group or anon-aromatic carbocyclic group. The C₄-C₆₀ carbocyclic group may be aring, such as benzene, a monovalent group, such as a phenyl group, or adivalent group, such as a phenylene group. In one or more embodiments,depending on the number of substituents connected to the C₄-C₆₀carbocyclic group, the C₄-C₆₀ carbocyclic group may be a trivalent groupor a quadrivalent group.

The term “C₂-C₆₀ heterocyclic group” as used herein refers to a grouphaving the same structure as the C₄-C₆₀ carbocyclic group, except thatas a ring-forming atom, at least one heteroatom selected from N, O, Si,P, and S is used in addition to carbon (the number of carbon atoms maybe in a range of 2 to 60).

In the present specification, at least one substituent of thesubstituted C₄-C₆₀ carbocyclic group, the substituted C₂-C₆₀heterocyclic group, the substituted C₃-C₁₀ cycloalkylene group, thesubstituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylenegroup, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensedpolycyclic group, the substituted divalent non-aromatic condensedheteropolycyclic group, the substituted C₁-C₆₀ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected is from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently beselected from is hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group,a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀alkyl group substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, and a cyano group, a C₆-C₆₀ aryl group substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, and a cyano group,a biphenyl group, and a terphenyl group.

The term “Ph” as used herein refers to a phenyl group, the term “Me” asused herein refers to a methyl group, the term “Et” as used hereinrefers to an ethyl group, the term “ter-Bu” or “Bu^(t)” as used hereinrefers to a tert-butyl group, and the term “OMe” as used herein refersto a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl groupsubstituted with a phenyl group”. In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group” as used herein refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a phenyl group having, as a substituent, a C₆-C₆₀ aryl groupsubstituted with a C₆-C₆₀ aryl group.

*, *′, and *″, as used herein, unless defined otherwise, each refer to abinding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments and an organiclight-emitting device according to embodiments will be described indetail with reference to Synthesis Examples and Examples. The wording “Bwas used instead of A” used in describing Synthesis Examples refers tothat an identical molar equivalent of B was used in place of A.

SYNTHESIS EXAMPLES Synthesis Example 1: Synthesis of Compound 1

1) Synthesis of Intermediate [1-A]

1-bromo-2-nitrobenzene (1.0 eq), 4-methoxy phenylboronic acid (1.2 eq),K₂CO₃ (2.0 eq), and 0.01 g of Pd(dppl)₂Cl₂ catalyst were added,dissolved in a dimethyl sulfoxide (DMSO) solution, and then stirred at atemperature of 130 _(i)É for 6 hours until the reactant was completelyconsumed. After the reaction mixture was cooled to room temperature, anorganic layer was extracted therefrom three times by using ethyl acetateand water and separated from the reaction mixture. The obtained organiclayer was dried by using magnesium sulfate and concentrated, and columnchromatography was used to obtain Intermediate [1-A] (yield: 78%).

2) Synthesis of Intermediate [1-B]

Intermediate [1-A] (1.2 eq) was dissolved in dichloromethane (0.1 M),and PPh₃ (2.0 eq) was slowly added thereto while stirring at atemperature of −78 _(i)É. Then, the reaction to mixture was stirred for2 hours. After the reaction mixture was cooled to room temperature, anorganic layer was extracted therefrom three times by using ethyl acetateand water and separated from the reaction mixture. The obtained organiclayer was dried by using magnesium sulfate and concentrated to obtainIntermediate [1-B] (yield: 61%).

3) Synthesis of Intermediate [1-C]

Intermediate [1-B] (1.5 eq), methyl-2-bromoicotinate (1.1 eq), CuI (0.03g), K₂CO₃ (2.0 eq), and L-Proline (0.04 eq) were dissolved in toluene(0.1 M) and stirred at a temperature of 130 _(i)É for 12 hours. Afterthe reaction mixture was cooled to room temperature, and an organiclayer was dried by using magnesium sulfate and concentrate, and columnchromatography was used to obtain Intermediate [1-C] (yield: 59%).

4) Synthesis of Intermediate [1-D]

Intermediate [1-C] (1.3 eq) and Grignard reagent (1.3 eq) were dissolvedin tetrahydrofuran (THF) and stirred at room temperature for 24 hoursuntil the reactant was completely consumed. An organic layer wasextracted therefrom three times by using dichloromethane and water. Theobtained organic layer was dried by using magnesium sulfate andconcentrated, and column chromatography was used to obtain Intermediate[1-D] (yield: 45%).

5) Synthesis of Intermediate [1-E/1-F]

Intermediate [1-D] (1.0 eq), di-p-tolyliodonium trifluoromethanesulfonate (1.5 eq), and CuOAc (0.1 eq) were dissolved in toluene (0.1 M)and stirred at a temperature of 100 _(i)É for 10 hours until thereactant was completely consumed. A hydrogenation reaction was performedon obtained Intermediate [1-E] (1.0 eq) under Pd/C catalyst (0.02 g) ata high temperature (500K) and a high pressure (10 atm) to obtainIntermediate [1-F] (yield: 74%).

6) Synthesis of Intermediate [1-G/1-H/1]

Intermediate [1-F] (1.2 eq), 1-(3-boromo-phenyl)-1H-imidazole (1.0 eq),CuI (0.02 eq), tBuONa (2.0 eq), and L-Proline (0.04 eq) were dissolvedin toluene (0.1 M) and stirred at a temperature of 160 _(i)É for 48hours. Obtained Intermediate [1-G] was cooled to room temperature, andan organic layer was extracted therefrom three times by using CH₂Cl₂ andwater. The obtained organic layer was dried by using Na₂SO₃ andconcentrated, and chromatography was used to obtain Intermediate [1-H]ligand compound (yield: 85%). The obtained Intermediate [1-H] ligandcompound (1.0 eq), dichloro(1,5-cyclootadienyl) platinum (II) (1.05 eq),and sodium acetate (3.0 eq) were dissolved in THF (0.1 M) and stirred ata temperature of 120 _(i)É for 72 hours in a nitrogen atmosphere. Thereactant was cooled to room temperature, and a solvent was removedtherefrom under reduced pressure. The concentrated reactant wasdissolved in dichloromethane, and the remaining precipitate was filteredoff. The filtrate was purified by column chromatography to obtainCompound 1 (yield: 20%).

MS cald. For C₃₀H₂₂N₄OPt (MS+1), m/z 649.6; observed 649.6.

Synthesis Example 2: Synthesis of Compound 3

1) Synthesis of Intermediate [3-A]

1-bromo-3-chloro-2-nitrobenzene (1.0 eq), 4-methoxy phenylboronic acid(1.2 eq), K₂CO₃ (2.0 eq), and 0.01 g of Pd(dppl)₂Cl₂ catalyst wereadded, dissolved in a DMSO solution, and then stirred at a temperatureof 130 _(i)É for 6 hours until the reactant was completely consumed.After the reaction mixture was cooled to room temperature, an organiclayer was extracted therefrom three times by using ethyl acetate andwater and separated from the reaction mixture. The obtained organiclayer was dried by using magnesium sulfate and concentrate, and columnchromatography was used to obtain Intermediate [3-A] (yield: 75%).

2) Synthesis of Intermediate [3-B]

Intermediate [3-A] (1.2 eq) was dissolved in dichloromethane (0.1 M),and PPh₃ (2.0 eq) was slowly added thereto while stirring at atemperature of −78 _(i)É. Then, the reaction to mixture was stirred for2 hours After the reaction mixture was cooled to room temperature, anorganic layer was extracted therefrom three times by using ethyl acetateand water and separated from the reaction mixture. The obtained organiclayer was dried by using magnesium sulfate and concentrated to obtainIntermediate [3-B] (yield: 59%).

3) Synthesis of Intermediate [3-C]

Intermediate [3-B] (1.5 eq), 2-bromo-3-vinylpyridine (1.1 eq), Pd₂(dba)₃(0.03 g), PPh₃ (2 eq), and t-BuONa (2.0 eq) were dissolved in dioxane(0.1 M) and stirred at a temperature of 130 _(i)É for 12 hours. Afterthe reaction mixture was cooled to room temperature, an organic layerwas dried by using magnesium sulfate and concentrated, and columnchromatography was used to obtain Intermediate [3-C] (yield: 51%).

4) Synthesis of Intermediate [3-D]

Intermediate [3-C] (1.3 eq), Pd₂(dba)₃ (0.03 g), DavePhos (1.3 eq), andt-BuONa (0.02 eq) were dissolved in dioxane and stirred at roomtemperature for 24 hours until the reactant was completely consumed. Anorganic layer was extracted therefrom three times by usingdichloromethane and water. The obtained organic layer was dried by usingmagnesium sulfate and concentrated, and column chromatography was usedto obtain Intermediate [3-D](yield: 41%).

5) Synthesis of Intermediate [3-E/3-F]

Intermediate [3-D] (1.0 eq), di-p-tolyliodonium trifluoromethanesulfonate (1.5 eq), and CuOAc (0.1 eq) were dissolved in toluene (0.1 M)and stirred at a temperature of 100 _(i)É for 10 hours until thereactant was completely consumed. A hydrogenation reaction was performedon obtained Intermediate [3-E] (1.0 eq) under Pd/C catalyst (0.02 g) ata high temperature (500K) and a high pressure (10 atm) to obtainIntermediate [3-F] (yield: 42%).

7) Synthesis of Intermediate and Final Compound [3-G/3-H/3]

Intermediate [3-F] (1.2 eq), 1-(3-boromo-phenyl)-1H-imidazole (1.0 eq),CuI (0.02 eq), tBuONa (2.0 eq), and L-Proline (0.04 eq) were dissolvedin toluene (0.1 M) and stirred at a temperature of 160 _(i)É for 48hours. Obtained Intermediate [3-G] was cooled to room temperature, andan organic layer was extracted therefrom three times by using CH₂Cl₂ andwater. The obtained organic layer was dried by using Na₂SO₃ andconcentrated, and chromatography was used to obtain Intermediate [3-H]ligand compound (yield: 80%). The obtained Intermediate [3-H] ligandcompound (1.0 eq), dichloro(1,5-cyclootadienyl) platinum to (II) (1.05eq), and sodium acetate (3.0 eq) were dissolved in THF (0.1 M) andstirred at a temperature of 120 _(i)É for 72 hours in a nitrogenatmosphere. The reaction was cooled to room temperature, and a solventwas removed therefrom under reduced pressure. The concentrated reactantwas dissolved in dichloromethane, and the remaining precipitate wasfiltered out. The filtrate was purified by column chromatography toobtain Compound 3 (yield: 22%).

MS cald. For C₂₉H₂₀N₄OPt (MS+1), m/z 635.6; observed 635.6.

Compounds 2, 4, and 5 other than Compounds 1 and 3 were synthesized byreferring to the methods provided in Synthesis Examples 1 and 2.

Evaluation Example 1: Quantum Simulation Analysis

Energy level values of ³MLCT states of Compounds 1 to 5 and Compounds Ato C as Comparative Examples were evaluated by using B3LYP functional.Pt and Ir were evaluated by using a density functional theory (DFT)method employing Gaussian program structurally optimized at a level ofLANL2DZ basis set, and C, H, N, and O atoms were evaluated by using aDFT method employing Gaussian program structurally optimized at a levelof 6-311G(d,p) basis set. The ground state energy and triplet energywere calculated based on the ³MC state energy level values. E₃ wascalculated by using Equation 1 as described above and is to shown inTable 1.

TABLE 1 Compound T₁ (eV) ³MC (Kcal/mol) ³MCLT E₃ (kcal/mol) Compound 12.68 27.4 12.11 27.4 Compound 2 2.65 27.2 12.32 27.2 Compound 3 2.6527.4 12.24 27.4 Compound 4 2.61 — 19.50 — Compound 5 2.79 31.0 24.0831.0 Compound A 2.71 9.87 9.82 9.87 Compound B 2.14 22.45 15.32 6.08Compound C 2.39 10.96 22.08 10.96

From Table 1, the E₃ values of Compounds 1 to 5 were remarkably greaterthan the E₃ values of Compounds A to C. Therefore, since the probabilitythat Compounds 1 to 5 transition from the ³MCLT state to thenon-emission state, that is, the ³MC state decreases, the stability ofCompounds 1 to 5 in the excited state may be excellent, and theefficiency and lifespan of the organic light-emitting device includingthe organometallic compound may increase.

Example 1

As a substrate and an ITO anode, a 15 Ω/cm² (1,200 Å) ITO glasssubstrate from Corning was cut to a size of 50 mm×50 mm×0.7 mm,sonicated with isopropyl alcohol and pure water each for 5 minutes, andthen cleaned by exposure to ultraviolet rays and ozone for 30 isminutes. Then, the ITO glass substrate was provided to a vacuumdeposition apparatus.

2-TNATA was vacuum-deposited on the ITO anode formed on the ITO glasssubstrate to form a hole injection layer having a thickness of 600 Å,and NPB was vacuum-deposited on the hole injection layer to form atransport layer having a thickness of 300 Å.

Co-hosts BCPDS (bis(4-(9H-carbazol-9-yl)phenyl)diphenylsilane) andPOPCPA((4-(1-(4-(diphenylamino)phenyl)cyclohexyl)phenyl)diphenyl-phosphineoxide) (a BCPDS to POPCPA weight ratio was 1:1) and a dopant Compound 1were co-deposited on the hole transport layer at a co-host to dopantweight ratio of 90:10 to form an emission layer having a thickness of300 Å.

TSPO1 (diphenyl(4-(triphenylsilyl)phenyl)-phosphine oxide) was depositedon the emission layer to form a hole blocking layer having a thicknessof 50 Å, Alq₃ was deposited on the hole blocking layer to form anelectron transport layer having a thickness of 300 Å, LiF was depositedon the electron transport layer to form an electron injection layerhaving a thickness of 10 Å, and Al was vacuum-deposited on the electroninjection layer to form a cathode having a to thickness of 3,000 Å,thereby completing the manufacture of an organic light-emitting device.

Examples 2 and 3 and Comparative Example 1

Organic light-emitting devices were manufactured in the same manner asin Example 1, except that Compounds shown in Table 2 were each usedinstead of Compound 1 as is a dopant in forming an emission layer.

Evaluation Example 2

The driving voltage, current density, lifespan (LT₉₅), luminescenceefficiency, emission color, and maximum emission wavelength of theorganic light-emitting devices manufactured according to Examples 1 to 3and Comparative Example 1 were measured by using Keithley SMU 236 and aluminance meter PR650, and results thereof are shown in Table 2.

TABLE 2 Dopant in Driving Current Lifespan Emission emission voltagedensity (LT₉₅) Emission wavelength layer (V) (mA/cm²) (hr) color (nm)Example 1 1 4.8 0.383 45 Blue color 464 Example 2 3 4.6 0.356 58 Bluecolor 468 Example 3 5 5.1 0.427 33 Blue color 445 Comparative A 4.60.320 10 Blue color 467 Example 1

Referring to Table 2, it is confirmed that the organic light-emittingdevices manufactured according to Examples 1 to 3 have remarkablyexcellent current density and lifespan characteristics, as compared withthe organic light-emitting device manufactured according to ComparativeExample 1.

The organic light-emitting device including the organometallic compoundmay to have a low driving voltage, high luminance, high efficiency, anda long lifespan.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; anorganic layer between the first electrode and the second electrode andcomprising an emission layer; and at least one of an organometalliccompound represented by Formula 1:M(L₁)_(n1)(L₂)_(n2)  <Formula 1>

wherein, in Formula 1, M is selected from platinum (Pt), palladium (Pd),copper (Cu), silver (Ag), gold (Au), rhodium (Rh), iridium (Ir),ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium(Hf), europium (Eu), terbium (Tb), and thulium (Tm), in Formula 1, L₁ isa ligand represented by Formula 2-1 or 2-2, and n1 is 1, 2, or 3,wherein, when n1 is 2 or more, two or more L₁(s) are identical to ordifferent from each other, in Formula 1, L₂ is a ligand represented byFormula 3, and n2 is 0, 1, or 2, wherein, when n2 is 2 or more, two ormore L₂(S) are identical to or different from each other, the sum of n1and n2 in Formula 1 is 2 or 3, in Formula 1, L₁(s) in the number of n1and L₂(S) in the number of n2 are optionally linked to each other via asingle bond, a first linking group, a substituted or unsubstitutedC₅-C₆₀ carbocyclic group, or a substituted or unsubstituted C₁-C₆₀heterocyclic group, the first linking group is selected from*″—N(R₄)—*′″, *″—B(R₄)—*′″, *″—P(R₄)—*′″, *″—C(R₄)(R₅)—*′″,*″—Si(R₄)(R₅)—*′″, *″—Ge(R₄)(R₅)—*′″, *″—S—*′″, *″—Se—*′″, *″—O—*′″,*″—C(═O)—*′″, *″—S(═O)—*′″, *″—S(═O)₂—*′″, *″—C(R₄)═*′, *″═C(R₄)—*′″,*″—C(R₄)═C(R₅)—*′″, *″—C(═S)*′″, and *″—C≡C—*′″, A₁ in Formula 2-1 isselected from a C₅-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclicgroup, X₁ and X₂ in Formula 2-1 are each independently N or C(R₃), inFormula 2-2, X₁₁ and X₁₂ are each C(R₁₅), and X₁₃ is N or C(R₁₅), T₂₁ inFormula 3 is selected from *″—N(R₂₄)—*′″, *″—B(R₂₄)—*′″, *″—P(R₂₄)—*′″,*″—C(R₂₄)(R₂₅)—*″, *″—Si(R₂₄)(R₂₅)—*′″, *″—Ge(R₂₄)(R₂₅)—*′″, *″—S—*′″,*″—Se—*′″, *″—O—*′″, *″—C(═O)—*′″, *″—S(═O)—*′″, *″—S(═O)₂—*′″,*″—C(R₂₄)═*′, *″═C(R₂₄)—*′″, *″—C(R₂₄)═C(R₂₅)—*″, *″—C(═S)—*′″, and*″—C≡C—*″, R₁ to R₅, R₁₁ to R₁₅, and R₂₁ to R₂₅ in Formulae 2-1, 2-2,and 3 are each independently selected from hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁),—S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b1 in Formula 2-1 is an integer from 1to 6, wherein, when b1 is 2 or more, two or more R₁(s) are identical toor different from each other, b21 to b23 in Formula 3 are eachindependently an integer from 1 to 3, wherein, when b21 is 2 or more,two or more R₂₁(s) are identical to or different from each other, whenb22 is 2 or more, two or more R₂₂(s) are identical to or different fromeach other, and when b23 is 2 or more, two or more R₂₃(s) are identicalto or different from each other, in Formulae 2-1, 2-2, and 2-3, twoneighboring substituents among R₁(s) in the number of b1, R₂, R₃, R₁₁ toR₁₄, R₁₅, R₂₁(S) in the number of b21, R₂₂(S) in the number of b22,R₂₃(S) in the number of b23, R₂₄, and R₂₅ are optionally linked to eachother to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group ora substituted or unsubstituted C₁-C₃₀ heterocyclic group, a21 in Formula3 is an integer from 1 to 3, wherein, when a21 is 2 or more, two or moreT₂₁(s) are identical to or different from each other, * and *′ inFormulae 2-1 and 2-2 each indicate a binding site to M in Formula 1, and*″ and *′″ in Formulae 1 and 3 each indicate a binding site to aneighboring atom, at least one substituent of the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀ alkenyl group, the substitutedC₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, thesubstituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedC₁-C₆₀ heteroaryloxy group, the substituted C₁-C₆₀ heteroarylthio group,the substituted monovalent non-aromatic condensed polycyclic group, andthe substituted monovalent non-aromatic condensed heteropolycyclic groupis selected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenylgroup, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a C₁-C₆₀ alkyl group substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, and a cyano group, aC₆-C₆₀ aryl group substituted with at least one selected from deuterium,—F, —Cl, —Br, —I, and a cyano group, a biphenyl group, and a terphenylgroup.
 2. The organic light-emitting device of claim 1, wherein theorganometallic compound comprises a four-coordinate or six-coordinateligand and a metal atom (M₁), and an energy level of a triplet metalcentered state (³MC state) of the organometallic compound (E_(3MC)) ishigher than an energy level of a triplet metal-to-ligand charge transferstate (³MLCT state) of the organometallic compound (E_(3MLCT)).
 3. Theorganic light-emitting device of claim 1, wherein the organometalliccompound satisfies E₃≥5 kcal/mol, and E₃ is defined by Equation 1:E ₃ =∥E _(3MLCT) |−|E _(3MC)∥.  <Equation 1>
 4. The organiclight-emitting device of claim 1, wherein the first electrode is ananode, the second electrode is a cathode, the organic layer comprisesthe at least one of the organometallic compound, the organic layerfurther comprises a hole transport region between the first electrodeand the emission layer and an electron transport region between theemission layer and the second electrode, the hole transport regioncomprises at least one layer selected from a hole injection layer, ahole transport layer, a buffer layer, an emission auxiliary layer, andan electron blocking layer, and the electron transport region comprisesat least one layer selected from a hole blocking layer, an electrontransport layer, and an electron injection layer.
 5. The organiclight-emitting device of claim 4, wherein the emission layer comprisesthe at least one of the organometallic compound.
 6. The organiclight-emitting device of claim 1, wherein the emission layer emits bluelight having a maximum emission wavelength of about 440 nm to about 490nm.
 7. The organic light-emitting device of claim 4, wherein the holetransport region comprises a p-dopant having a lowest unoccupiedmolecular orbital (LUMO) energy level of −3.5 eV or less.
 8. Anorganometallic compound represented by Formula 1:M(L₁)_(n1)(L₂)_(n2)  <Formula 1>

wherein, in Formula 1, M is selected from platinum (Pt), palladium (Pd),copper (Cu), silver (Ag), gold (Au), to rhodium (Rh), iridium (Ir),ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium(Hf), europium (Eu), terbium (Tb), and thulium (Tm), in Formula 1, L₁ isa ligand represented by Formula 2-1 or 2-2, and n1 is 1, 2, or 3,wherein, when n1 is 2 or more, two or more L₁(s) are identical to ordifferent from each other, in Formula 1, L₂ is a ligand represented byFormula 3, and n2 is 0, 1, or 2, wherein, when is n2 is two or more, twoor more L₂(s) are identical to or different from each other, the sum ofn1 and n2 in Formula 1 is 2 or 3, L₁(s) in the number of n1 and L₂(S) inthe number of n2 in Formula 1 are optionally linked to each other via asingle bond or a first linking group, the first linking group isselected from *″—N(R₄)—*′″, *″—B(R₄)—*′″, *″—P(R₄)—*′″,*″—C(R₄)(R₅)—*′″, *″—Si(R₄)(R₅)—*′″, *″—Ge(R₄)(R₅)—*′″, *″—S—*′″,*″—Se—*′″, *″—O—*′″, *″—C(═O)—*′″, *″—S(═O)—*′″, *″—S(═O)₂—*′″,*″—C(R₄)═*′, *″═C(R₄)—*′″, *″—C(R₄)═C(R₅)—*′″, *″—C(═S)—*′″, and*″—C≡C—*′″, A₁ in Formula 2-1 is selected from a C₅-C₆₀ carbocyclicgroup and a C₁-C₆₀ heterocyclic group, X₁ and X₂ in Formula 2-1 are eachindependently N or C(R₃), X₁₁ and X₁₂ in Formula 2-2 are each C(R₁₅),and X₁₃ is N or C(R₁₅), T₂₁ in Formula 3 is selected from *″—N(R₂₄)—*′″,*″—B(R₂₄)—*′″, *″—P(R₂₄)—*′″, *″—C(R₂₄)(R₂₅)—*′, *″—Si(R₂₄)(R₂₅)—*′″,*″—Ge(R₂₄)(R₂₅)—*′″, *″—S—*′″, *″—Se—*′″, *″—O—*′″, *″—C(═O)—*′″,*″—S(═O)—*′″, *″—S(═O)₂—*′″, *″—C(R₂₄)═*′, *″═C(R₂₄)—*′″,*″—C(R₂₄)═C(R₂₅)—*′″, *″—C(═S)—*′″, and *″—C≡C—*′″, R₁ to R₅, R₁₁ toR₁₅, and R₂₁ to R₂₅ in Formulae 2-1, 2-2, and 3 are each independentlyselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b1 in Formula2-1 is an integer from 1 to 6, wherein, when b1 is 2 or more, two ormore R₁(s) are identical to or different from each other, b21 to b23 inFormula 3 are each independently an integer from 1 to 3, wherein, whenb21 is 2 or more, two or more R₂₁(s) are identical to or different fromeach other, when b22 is 2 or more, two or more R₂₂(S) are identical toor different from each other, and when b23 is 2 or more, two or moreR₂₃(s) are identical to or different from each other, in Formulae 2-1,2-2, and 2-3, two neighboring substituents among R₁(s) in the number ofb1, R₂, R₃, R₁₁ to R₁₄, R₁₅, R₂₁(s) in the number of b21, R₂₂(s) in thenumber of b22, R₂₃(s) in the number of b23, R₂₄, and R₂₅ are optionallylinked to each other to form a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, a21 in Formula 3 is an integer from 1 to 3, wherein, when a21 is2 or more, two or more T₂₁(s) are identical to or different from eachother, * and *′ in Formulae 2-1 and 2-2 each indicate a binding site toM in Formula 1, and *″ and *′″ in Formulae 1 and 3 each indicate abinding site to a neighboring atom, at least one substituent of thesubstituted C₅-C₃₀ carbocyclic group, the substituted C₁-C₃₀heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substitutedC₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, thesubstituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted C₁-C₆₀ heteroaryloxy group, thesubstituted C₁-C₆₀ heteroarylthio group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group is selected from:deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q l), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a C₁-C₆₀ alkyl group substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, and a cyano group, aC₆-C₆₀ aryl group substituted with at least one selected from deuterium,—F, —Cl, —Br, —I, and a cyano group, a biphenyl group, and a terphenylgroup.
 9. The organometallic compound of claim 8, wherein M in Formula 1is selected from Pt, Ir, Pd, Cu, Ag, and Au.
 10. The organometalliccompound of claim 8, wherein, in Formula 1, n1 is 1 and n2 is 1; or n1is 3 and n2 is
 0. 11. The organometallic compound of claim 8, wherein A₁in Formula 2-1 is selected from: a benzene group, a pyridine group, apyrimidine group, a pyrazine group, a pyridazine group, a triazinegroup, a cyclopentane group, a cyclopentadiene group, a furan group, athiophene group, a pyrrole group, a silole group, an oxazole group, anisoxazole group, an oxadiazole group, an isozadiazole group, anoxatriazole group, an isoxatriazole group, a thiazole group, anisothiazole group, a thiadiazole group, an isothiadiazole group, athiatriazole group, an isothiatriazole group, a pyrazole group, animidazole group, a triazole group, a 1,2,4-triazole group, a tetrazolegroup, an azasilole group, a diazasilole group, a triazasilole group, acyclohexane group, and a cyclohexene group; and a benzene group, apyridine group, a pyrimidine group, a pyrazine group, a pyridazinegroup, a triazine group, a cyclopentane group, a cyclopentadiene group,a furan group, a thiophene group, a pyrrole group, a silole group, anoxazole group, an isoxazole group, an oxadiazole group, an isozadiazolegroup, an oxatriazole group, an isoxatriazole group, a thiazole isgroup, an isothiazole group, a thiadiazole group, an isothiadiazolegroup, a thiatriazole group, an isothiatriazole group, a pyrazole group,an imidazole group, a triazole group, a 1,2,4-triazole group, atetrazole group, an azasilole group, a diazasilole group, a triazasilolegroup, a cyclohexane group, and a cyclohexene group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a cyanogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group,a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group,a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a perylenyl group, a pentacenyl group, a pyrrolylgroup, a thiophenyl group, a furanyl group, a silolyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolylgroup, an isoindolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, anisoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, abenzoquinazolinyl group, a cinnolinyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, abenzosilolyl group, a benzothiazolyl group, a benzoisothiazolyl group, abenzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, atetrazolyl group, a thiadiazolyl group, an oxadiazolyl group, atriazinyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolylgroup, a naphthobenzofuranyl group, a naphthobenzothiophenyl group, anaphthobenzosilolyl group, a dibenzocarbazolyl group, a dinaphthofuranylgroup, a dinaphthothiophenyl group, a dinaphtho silolyl group, animidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinylgroup, a thiazolopyridinyl group, a benzonaphthyridinyl group, anazafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolylgroup, an azadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, an indenopyrrolyl group, an indolopyrrolylgroup, an indeno carbazolyl group, an indolocarbazolyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)(Q₃₁), —S(═O)₂(Q₃₁), —P(═O)(Q₃₁)(Q₃₂), and —P(═S)(Q₃₁)(Q₃₂), andQ₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, aC₁-C₆₀ alkyl group substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, and a cyano group, a C₆-C₆₀ aryl groupsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,and a cyano group, a biphenyl group, and a terphenyl group.
 12. Theorganometallic compound of claim 8, wherein X₁ and X₂ in Formula 2-1 areeach C(R₃), and X₁₃ in Formula 2-2 is C(R₁₅).
 13. The organometalliccompound of claim 8, wherein, in Formula 3, T₂₁ is *″—C(R₂₄)(R₂₅)—*′″and a21 is 1 or
 2. 14. The organometallic compound of claim 8, whereinR₁ to R₅, R₁₁ to R₁₅, and R₂₁ to R₂₅ in Formulae 2-1, 2-2, and 3 areeach independently selected from: hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, and C₁-C₂₀alkoxy group; a cyclopentyl group, a cyclohexyl group, a phenyl group, anaphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinylgroup, a pyridazinyl group, a pyrrolyl group, an indolyl group, anisoindolyl group, an indazolyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, and a triazinyl group; and a cyclopentyl group, acyclohexyl group, a phenyl group, a naphthyl group, a pyridinyl group, apyrimidinyl group, a pyrazinyl group, a pyridazinyl group, an indolylgroup, an isoindolyl group, an indazolyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, and a triazinyl group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group,a cyclohexyl group, a phenyl group, a naphthyl group, a pyridinyl group,a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, an indolylgroup, an isoindolyl group, an indazolyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, and a triazinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),—N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and—P(═O)(Q₃₁)(Q₃₂); and —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂),—C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), and Q₁ to Q₃ and Q₃₁ to Q₃₃are each independently selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a cyano group, a C₁-C₂₀ alkyl group, a C₂-C₂₀ alkenyl group, aC₂-C₂₀ alkynyl group, a C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₂₀ aryl group, a C₁-C₂₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, and amonovalent non-aromatic condensed heteropolycyclic group.
 15. Theorganometallic compound of claim 8, wherein R₂ in Formula 2-1 isselected from: a C₁-C₂₀ alkyl group, —N(Q₁)(Q₂), and a phenyl group; anda C₁-C₂₀ alkyl group, —N(Q₁)(Q₂), and a phenyl group, each substitutedwith a C₁-C₂₀ alkyl group, and Q₁ and Q₂ are each independently a C₁-C₂₀alkyl group.
 16. The organometallic compound of claim 8, wherein R₁₁ andR₁₂ in Formula 2-2 are each independently selected from hydrogen, —F,—Cl, a cyano group, a C₁-C₂₀ alkyl group, and a phenyl group.
 17. Theorganometallic compound of claim 8, wherein n1 and n2 are each 1, and L₁is a group represented by Formula 2-1, and one of R₁(s) in the number ofb1 and one of neighboring R₂₃(S) in the number of b23 are linked to eachother via a single bond or a first linking group.
 18. The organometalliccompound of claim 8, wherein n1 is 3, and L₁ is a group represented byFormula 2-2, X₁₃(s) in three L₁(s) are each C(R₁₅), three R₁₄(s) inthree L₁(s) are linked to each other via a substituted or unsubstitutedC₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group, and three R₁₅(s) in three L₁(s) are linked to eachother via a substituted or unsubstituted C₅-C₆₀ carbocyclic group or asubstituted or unsubstituted C₁-C₆₀ heterocyclic group.
 19. Theorganometallic compound of claim 8, wherein the organometallic compoundis a group represented by one of Formulae 1-1 to 1-5:

wherein, in Formulae 1-1 to 1-5, L₁₁ to L₁₅ may each independently beselected from a single bond, *″—N(R₄)—*′″, *″—B(R₄)—*′″, *″—P(R₄)*′″*,*″—C(R₄)(R₅)—*′″, *″—Si(R₄)(R₅)—*′″, *″—Ge(R₄)(R₅)—*′″, *″—S—*′″,*″—Se—*′″, *″—O—*′″, *″—C(═O)—*′″, *″—S(═O)—*′″, *″—S(═O)₂—*″,*″—C(R₄)═*′, *″═C(R₄)—*′″, *′″—C(R₄)═C(R₅)—*′″, *″—C(═S)—*′″, and*″—C≡C—*′″, c11 to c15 are each independently an integer from 1 to 3,wherein, when c11 is 2 or more, two or more L₁₁(s) are identical to ordifferent from each other, when c12 is 2 or more, two or more L₁₂(s) areidentical to or different from each other, when c13 is 2 or more, two ormore L₁₃(s) are identical to or different from each other, when c14 is 2or more, two or more L₁₄(s) are identical to or different from eachother, and c15 is 2 or more, two or more L₁₅(s) are identical to ordifferent from each other, Ar₁ and Ar₂ are each independently selectedfrom a substituted or unsubstituted trivalent C₅-C₃₀ carbocyclic group,a substituted or unsubstituted trivalent C₁-C₃₀ heterocyclic group, or agroup represented by

and *″, *′″, and *″″ each indicate a binding site to a neighboring atom,c11 and c12 are each independently an integer from 1 to 3, wherein, whenc11 is 2 or more, two or more L₁₁(s) are identical to or different fromeach other, and when c12 is 2 or more, two or more L₁₂(s) are identicalto or different from each other, and R_(1a) to R_(1c), R_(3a) to R_(3b),R_(15a) to R_(15b), R_(21a) to R_(21c), R_(22a) to R_(22c), R_(23a) toR_(23b), R_(24a) to R_(24b), R_(25a) to R_(25b), and R₃₀ are eachindependently the same as defined in connection with R₁, R₃, R₁₅, andR₂₁ to R₂₅ in claim 1, and R₂, R₄, R₅, and R₁₁ to R₁₃ are eachindependently the same as defined in connection with R₂, R₄, R₅, and R₁₁to R₁₃ in claim
 1. 20. The organometallic compound of claim 8, whereinthe organometallic compound represented by Formula 1 is selected fromCompounds 1 to 14: